1. Field of the Invention
The present invention relates generally to book binding and more particularly to a device and method for preparing a book spine for binding.
2. Background Information
To form books (defined herein to include all sheet and signature assemblages), sheets or signatures typically are collated or assembled so that the sheets of the book are arranged in the desired order. U.S. Pat. No. 4,988,086 discloses, for example, an apparatus and method for forming sheet material assemblages. The sheets or signatures are stacked above continuously moving assemblers or pockets and dropped one-by-one into the pockets. The bottom of the pocket can open to release an assembled, but unbound, book.
To prepare books for binding, the sheets or signatures must then be registered, so that all edges are even. The spine will be flat if a flatback book is to be formed. If signatures rather than individual sheets are collated, the backbone of the book typically will be sawed so that individual sheets within each signature present themselves at the spine.
U.S. Pat. Nos. 4,925,354 and 4,556,353 disclose methods for applying an adhesive to the spine of a book. The book is gripped from the top by clamps to expose the spine of the book. The spine of the book has a length greater than a width of the spine, and is flat. As the spine travels in a direction parallel to the length of the spine, an adhesive is applied by rollers or applicators.
The above-referenced patents have the disadvantage that several separate devices are require to collate, register and bind the books. Moreover, transfer of the books between the collating machines, registering machines and the clamps is required. Each transfer point increases the chances for malfunction or a reduction in quality, such as bent edges or misalignment of the pages.
Moreover, transporting the book parallel to the spine length results in high linear velocities. The clamping mechanism must be substantial to hold the book, especially if the backbone is to be cut. The time for the glue to set is also limited, in that it is impractical with high velocities to provide a track having a long enough length for a clamping system to hold the book before the book must be delivered from the clamp.
An object of the present invention is to provide a method and device for preparing a book spine for binding, with the device and the method providing improved register characteristics. Another alternate or additional object of the present invention is to provide an angled book spine. Yet another alternate or additional object of the present invention is to permit for more efficient binding of the book spine.
The present invention provides a method for preparing a book spine including delivering a plurality of products against a spine stop so as to form a book spine, the plurality of products contacting a hinged wall. The hinged wall has a first section and a second section separated by a pivot. The spine stop is then moved away from the book spine, and the printed products are bent about the pivot. xe2x80x9cProductsxe2x80x9d as defined herein may include sheets and/or signatures.
The bending preferably occurs by holding a lower section of the products firmly between the second section of the hinged wall and a packer, and then rotating the second section about the pivot. A skew clamp then preferably holds an upper section of the products against the first section of the hinged wall, the packer is released, and the second section may returned in the direction of its original position.
As a result, the products move downwardly with respect to the hinged wall, thus providing an increased clearance between the book spine and the edge of the hinged wall. Moreover, a skew occurs for all the products, so that an angled spine results. Advantageously, the angled spine allows for improved application of a glue to bind the book. The skew angle preferably is between zero and thirty degrees.
Once the second section is returned to its original position, the packer may again press the book against the second section of the hinged wall and clamp the book for gluing. Minor adjustments to the angle of the spine can be made by moving the second section and the packer.
A glue wheel, advantageously having an axis of rotation perpendicular to the direction of travel of the book, may then apply glue to the spine. Advantageously, the products may travel in a direction perpendicular to the length of the spine while the spine is glued. The spine angle preferably is such that the spine edge is parallel to the direction of travel and tangent to the glue wheel. The glue wheel, which can rotate so as to apply glue in the same direction as the book travel direction, applies the glue to the spine. The tangential velocity of the glue wheel preferably is about the same (within +/xe2x88x925%) as the velocity of the books.
If water based, the glue can be dried by drying equipment to shorten the setting time.
To deliver the books the packer is opened and the books may fall by gravity to a conveyor or may be removed by a gripper conveyor.
When used with signatures, the present method preferably includes press-pasted signatures so as not to require the use of sawing or roughing of the backbone before gluing. However, it is conceivable that the present invention could also include a sawing step to shape angled spines.
The present invention also includes a device for preparing a book spine comprising a plurality of pockets, each pocket having a wall having a first section and a second section, the second section being pivotally connected to the first section. Each pocket also has a packer and a spine stop removably located at a lower end of the second section for contacting a spine end of products, the wall and the packer supporting the products for pivotal movement.
The pivotal movement of the products and the wall permits for the products to move downwardly with respect to the pocket and also permits skew angles to be formed in the products.
The pockets preferably move in a direction perpendicular to the spine, and in a horizontal plane.
The packer holds a lower part of the products against the second section. A skew clamp is provided for each pocket for holding an upper part of the products as the second section returns to an original position.
A glue wheel having an axis perpendicular to the motion of travel of the books may be provided. The axis preferably is in a horizontal plane.
The various moving parts of the pocket may be controlled by motors or by cam action.
When receiving new products, the side wall and the spine stop preferably form an angle with the vertical plane. Once the products are clamped by the packer and the spine stop is removed, the second section is then movable from the angled position to a vertical position. After the skew clamp is set, the packer may be removed and the second section returned to the angled position.
The present invention also provides a method for gluing a spine of a book comprising the steps of creating an angled spine, moving the angled spine in a direction of travel, the spine length being perpendicular to the direction of travel, and applying glue to the angled spine.
xe2x80x9cBookxe2x80x9d as defined herein can mean any type of sheet or signature assemblage, including but not limited to, covered printed products, paper booklets, and magazines.